The only criticism of Johnson is the unknown quantity on how he'd fare against accurate combination punches. I assume he'd utilise more head movement and block as opposed to parrying.
It's simple really. If you believe boxing hasn't evolved in 100 years and a peak 1908-1910 Johnson represents the pinnacle of the sport then you go with him. If you believe boxing has incrementally improved over the many decades since Johnson than you go with Kovalev and Tua.
Even then you migth go with Johnson, on the basis that Kovalev was too small, and Tua was not the best or brightest of his era.
Smaller men than Kovalev like Choynski and Ketchel put Johnson on his back, so he couldn't be dismissed out of hand as being too small for the job. Tua while not a historical great like Johnson, with his fairly advanced bob n weave pressure style, size and vicious power could give Johnson problems that he seldom would have had to face in his career. I wouldn't rule him out of either fight though, especially if he's given time to prepare under modern conditions.
only if you believe that evolution is the same as improvement. they aren't, or else how u explain human cant beat t.rex in the ring.
Can someone please remind me who the best heavyweight opponent that Johnson beat and what was Johnson's listed weight for that bout?
yeh cos humans r more "evolved", so. its about niche ie. environment, as you want to point out. and you'd be right.